Hollow Mesoporous Metal Organic Framework Single Crystals Enabled by Growth Kinetics Control for Enhanced Photocatalysis

Abstract

The tailored design of hollow mesoporous metal−organic framework (MOF) single crystals to realize the unimpeded mass transport and long‐range carrier migration for advanced photoelectric applications is attractive while being a major challenge. Here, a kinetically mediated micelle assembly strategy is presented to synthesize hollow UiO‐66(Ce) single crystals in 1,3,5‐trimethylbenzene (TMB)‐H2O emulsion system with Pluronic F127/P123 as dual surfactants. This synthesis features the employment of modulator acetic acid, which can coordinate growth kinetics of MOFs, allowing the nucleation of MOF on block polymer micelles and transforming the self‐assembly of block polymer/MOF composite monomicelles from water to TMB/H2O emulsion interface and the growth of MOF from aggregation to oriented attachment, and thus ensuring the formation of hollow mesoporous UiO‐66(Ce) single crystals. Moreover, a precise control in cavity diameter from ≈0 to ≈600 nm, mesopore structure from close to radial and dendritic can be achieved by tuning the amount of TMB and the ratio of F127/P123. As a result, the hollow mesoporous UiO‐66(Ce) single crystals with large radial mesopores (≈25 nm) and high surface area (≈1061 m2 g) exhibit excellent photocatalytic performance for H2 generation owing to enhanced permeability and suppressed electron‐hole combination.

From nano- to macroarchitectures: designing and constructing MOF-derived porous materials for persulfate-based advanced oxidation processes

“…Zhao and colleagues proposed a kinetically mediated micelle assembly strategy to prepare hollow UiO-66(Ce) with oriented mesopores (25 nm). 110 More recently, the Guan group developed a dual-template-directed successive assembly approach for the construction of mesoporous UiO-66-NH 2 with a hollow multi-shell nanoarchitecture (Fig. 7b).…”

Hierarchically Ordered Pore Engineering of Metal–Organic Framework‐Based Materials for Electrocatalysis

“…Similarly, Luo group synthesized the hollow UiO-66(Ce) with dendrite-like ordered mesoporous shells in TMB-H 2 O emulsion system with F127/P123 as the dual surfactants. [48] Especially, the formation process of UiO-66(Ce) with various nanostructures at varied concentrations of HAc modulator was investigated in details and a kinetically mediated micelle assembly process was proposed for constructing the hollow ordered mesoporous UiO-66(Ce). Furthermore, they also demonstrated a precise control in cavity diameter and mesopore structure transformation from close to radial and dendritic by tuning the amount of TMB and the ratio of F127/P123.…”

Enhanced Catalytic Activity through the Variation of Hierarchical Porosity in a Zr-Based Metal–Organic Framework

“…Metal–organic assemblies of some MOF precursors themselves are also known to act as templates resulting in mesopores, although the exact forms of the templates are unknown . Among them, there exist few examples, where the soft templates based on amphiphilic, lengthy surfactants and block copolymers that are stabilized in various forms of meso-aggregates, that have been used as porogens to introduce mesopores in UiO-MOF family with varying levels of pore characteristics and hierarchical porosity. − (Table S2). Our interest lies in the exploration of gemini surfactants, a unique class of dicationic surfactants as soft templates in the synthesis of HP MOFs. , In this work, we have used G 14–6–14 , a gemini surfactant, with hydrophilic quaternary ammonium-based dual-head groups, each containing a 14-C alkyl chain as the hydrophobic tail and a 6-C alkyl chain as the linker between the two-head groups (Figure S1 in the Supporting Information).…”